The objective of this project is to assess specific and non-specific parameters of cell-mediated immune reactivity in regional lymph node lymphocytes (LNL) and peripheral blood lymphocytes (PBL) of colorectal carcinoma patients. Data from twenty one (21) carcinoma and five (5) non-cancer surgery patients have been evaluated in either E- rosette assays, mixed leukocyte tumor cell cultures and/or lymphocyte stimulation test. These data have been correlated with the clinical stage of the disease. Differences in the LNL response of Duke's B and Duke's C patients have been observed in various of the test systems.